From the plaque:
municipal greenhouse was completed in 1879. It was patterned
after The Conservatory, Kew Gardens, England A
distinguished example of late Victorian style using early
techniques of mass production and assembly of simple glass
units.It was given to the City of San Francisco by public-spirited
Plaque placed by the State Department of Parks and Recreation in cooperation with the San Francisco Recreation and Park Commission and California Historical Society, November 19, 1970.